1. Field of the Invention
The present invention relates to a program use authorization method and a program use authorization program to prevent programs from being illegally installed or executed.
2. Description of the Related Art
The method of preventing illegal installation of programs by using a given identifier (ID) such as an install key (or a product key) is generally practiced. That is, when installing a program, a user inputs an install key in a computer. The computer collates the input install key with the install key in the program, and allows program installation if the input install key corresponds with the install key in the program.
An install key to be given to the user is, for example, described on a print enclosed in the package of a storage medium (such as a CD-ROM) storing a program, or described on mail to be sent to the user.
The legal user possessing the printed install key can install the program properly by inputting the install key at the time of installation.
However, others can easily know the printed install key by peeping at it: those other than the user with legal authority to use a program may install the program illegally after obtaining the install key.
To prevent such illegal conduct, a memory medium (an IC card, etc.) storing the install key is provided to the authorized user, and program installation is allowed on the condition that before a program is installed, the memory medium is connected to a device on which the program is installed. In other words, authorization is given by comparing the install key stored in a memory medium with the install key in the program. As the install key is stored in a memory medium, the install key itself is not displayed externally so that illegal installation can be prevented unless the memory medium itself is stolen and decrypted. If the memory medium is stolen and the install key is decrypted, however, illegal installation may be executed.
Therefore, even in the case of authorization using a memory medium, it is necessary to store the highest possible security level authorization data in the memory medium.
Likewise, in the above installation method using a memory medium, a program can freely be started and executed after the program is installed, and therefore, illegal use of the program cannot be prevented once the program is illegally installed.